The present invention is directed to a protective sleeve for use in connection with gas bottle post valves.
Gas bottles have a variety of end uses. Such end uses range from various industrial applications, where a specified gas is required (ranging from inert gases, such as nitrogen, to oxygen gas), to medical uses where oxygen is to be administered to a patient in need of oxygen. Such bottles have a tubular valve stem extending from an end of the gas bottle for engagement with a gas delivery tube or pipe.
A successful protective product for use with, for instance, the CGA 870 medical oxygen post (four sided elongated valve stem) should satisfy the following performance criteria: (a) prevent dust and debris from entering the oxygen supply port on the side of the valve stem, (b) be easy to install with a quick sliding motion, (c) remain firmly in place on the gas valve stem during handling, transportation, and storage before use by the gas user, and not prematurely rupture or become dislodged, (d) be easy for the end user to remove who is typically aged and/or infirmed, (e) serve to easily identify a full cylinder from an empty cylinder at a quick glance and at a distance of up to 50 feet, (f) provide “use evidence” (i.e., evidence that the compressed gas cylinder is still full, and has not previously been used), and (g) be translucent so that the valve seat sealing surface condition and valve pin index identifier can be inspected while the protective device is installed on the valve stem.
Such “use evidence” is particularly important because in emergency medical situations it is important for emergency personnel to be able to quickly identify which cylinder contains oxygen for use by a patient. “Use evidence” is also important to re-fillers of such compressed gas re-fillers, because full cylinders are frequently returned for credit when a full cylinder cannot be identified by content. This increases the re-filler's costs and affects the oxygen user's perception of value and quality provided by the re-filler.
It is also important that it be easy for the end user to remove the protective device from the valve stem. Many medical oxygen users are aged, and possibly also infirmed, individuals requiring home-based oxygen therapy. Any difficulty in removing the protective device could interfere with delivery of oxygen, or require assistance from another person if the protective device is not easily removed. An additional benefit sought for the protective device is the ability to physically protect the valve seat (the area between the bottom end of the protective device and the top of the compressed valve cylinder). Scratches and damage to the valve seat and post valve surface result in leak paths for oxygen to escape, which can result in explosion and/or fire.
The protective device must also address the needs of all who use or benefit from the protective device. Such parties include the compressed gas producers (who fill the gas bottles and initially install the protective device), the compressed gas distributors who receive the compressed gas bottles having the protective device, and the ultimate end users (home-based patients, hospitals, medical care personnel, etc.). Each level of distribution sometimes requires different attributes of the protective device. For instance, the compressed gas producer requires a protective device which is easy to install, is protective in nature, and locks into place. The distributor requires the protective device to be physically stable as installed, and not subject to being displaced from the valve stem during storage or transportation. The ultimate end users require the protective device to be physically stable as installed to provide “evidence of use” indication, and easy to remove. For example, some prior art devices with wrap-around locking means require the locking strap to be cut to remove the device.
Ease of installation has always been a problem with prior art valve stem protective devices. Shrink wrap devices require the device to be wet when applied, and also are required to dry or be dried by application of heat to cause the required shrinkage. Those with wrap-around locking straps are cumbersome to physically handle. Those which are four-sided band-like devices, as a result of their short length, may require finger pressure along the top of the device while at the same time running the fingers against the side of the valve stem. Due to the thin walls of the device, it is difficult to apply much downward pressure against the device with the installer's fingers. Also, due to the small contact area for the installer's fingers, the fingers will always rub against the side of the valve stem during installation. They may also require a special tool to install the device, or be heated to soften the device prior to installation.
The protective device most predominately used for the past 50 years is the elastic band protector described by U.S. Pat. No. 3,125,242 which has multiple shortcomings. Another widely used protective product used in the medical gas industry is the cellulose shrink wrap. The other products offered to the medical gas industry have deficiencies that limit their market acceptance. The “cellulose shrink wrap” product is basically an elongated wet cellulosic sleeve that slips over the valve stem, and is caused to shrink about the valve stem upon exposure to heat, or shrinks as it dries. The product has the disadvantage of requiring installers of the device to get their hands wet to install the device. The device additionally requires substantial time to dry and shrink at which time the cylinder and valve must be stationary. While this product provides a barrier to dust and dirt, it is not durable (it is subject to disintegration as the shrink wrap material is fragile) and provides no protection upon being struck. The cellulosic sleeve product also provides no inspection visibility of the valve seat and pin index condition as it is opaque, and it is often difficult for the end user to remove the shrunken sleeve prior to use. Further disadvantages include the shrink wrap prematurely dislodging if the cylinder is lifted by the valve stem (as commonly occurs in the industry), and the shrink wrap dislodging when exposed to moisture (as commonly occurs when shipped in open truck beds exposed to weather, rain and snow. The main advantage of this product is its low cost.
Several prior art gas valve protective products exist, including cellulose bands and shrink wrap, and those described by U.S. Pat. No. 5,397,012, U.S. Pat. No. 3,125,242, and U.S. Pat. No. 6,003,714. Each of these products provide certain benefits, but none provide all of the desired benefits. The device of U.S. Pat. No. 5,397,012 is essentially the same as that of U.S. Pat. No. 3,125,242 with the exception that the device is cut, opened, and has a ratchet locking mechanism. The device of U.S. Pat. No. 5,397,012 appears to have been developed in an attempt to improve on the installation shortcomings of the device of U.S. Pat. No. 3,125,242 which requires tools and/or other installation aids and requires substantial downward force for installation. However, in actual practice the device of U.S. Pat. No. 5,397,012 becomes very cumbersome to install by requiring two hands to pre-fold each corner of the device before assembly. The device additionally requires special attention to position on the valve post, while finding, orienting, positioning, and threading the ratchet tab into the ratchet locking mechanism at the back of the valve requires further focused attention by the installer. Because of the device's requirement to wrap around the valve post, the ratchet lock and tab become angled at an unnatural orientation requiring further installation care.
The product described by U.S. Pat. No. 5,397,012 is not easy to place on the valve stem and lock in place due to the small size of the locking strap. The locking strap, when locked into place, must also be cut or broken for the device to be removed from the valve stem. The product is also so small that it is difficult to determine from any distance the status (filled, unfilled) of the gas cylinder upon which it is placed. The thin strap can easily rupture and prematurely fall off if bumped in handling and transit. This device additionally requires two hands and substantial care and time to install.
The device described by U.S. Pat. No. 3,125,242 consists of a flexible band that is snug-fit onto the valve stem. As it is such a snug-fit on the valve stem, the band must either be softened in hot water to permit the band to be stretched over the valve stem, or a special tool must be used to assist in sliding the band over and onto the valve stem. A representative tool 16 is described at FIG. 1 of the U.S. Pat. No. 3,125,242. As described by the patent at column 3, lines 35-73, the band is placed around the circumference of the tool body, the tool body placed into engagement with the valve stem, and the band pushed off the tool body into snug engagement with the valve stem. This protective product is thus not easy to install upon the valve stem.
The protective device described by U.S. Pat. No. 6,003,714 is even more cumbersome than the protective device of U.S. Pat. No. 3,125,242. The device of this patent must be wrapped around the valve stem in covering position to the gas orifice, with one free end being locked into a locking mechanism of the other free end to maintain the device in place. The fact that this protective device is able to be wrapped around the valve stem (instead of being pulled over) attempts to solve the main problem with the protective device of U.S. Pat. No. 3,125,242, which is ease of installation. However, this solution is only partially successful, as the fact that one free end must be placed into the locking mechanism at the other end and pulled tight for locking purposes requires some dexterity and extra effort. This is a significant problem when these protective devices are placed on large numbers of compressed gas cylinder valve stems in an assembly line type of environment due to the manual labor involved. This type of protective device is also difficult to secure tightly around the valve body and is prone to becoming accidentally dislodged during normal handling.
Moss Plastic Parts, Ltd. sells a band-like gas cylinder valve “Type 3” protector which suffers from some of the same disadvantages as other prior art valve stem protectors, such as being band-like, and lacking the requisite flange(s). The Moss “Type 3” protector has corner configurations which permit the device to expand as needed, and as a result has a dimensionally unstable fit which results in an unreliable assembly onto the valve stem, and only has a single tear line along the corner of the device, which, together with the band-like design of the product, makes the product difficult to remove from engagement with the valve stem.
Thus, for over 50 years, despite the problems with prior art valve stem protective devices, no new product has been introduced prior to the inventor's patented product of U.S. Pat. No. 7,681,587 and the present invention which satisfactorily meets all of the criteria desired to be met for the protective product to be considered totally successful. Users want a single handed quick installation, easy low force, reliable gas valve stem protector.
A need accordingly exists for means by which a gas bottle may be modified to clarify whether gas has been delivered by the bottle, or whether the bottle is unused, and which does not suffer from any of the disadvantages suffered by conventional devices.